scholarly journals Detection of a 100,000 M ⊙ black hole in M31's Most Massive Globular Cluster: A Tidally Stripped Nucleus

2022 ◽  
Vol 924 (2) ◽  
pp. 48
Author(s):  
Renuka Pechetti ◽  
Anil Seth ◽  
Sebastian Kamann ◽  
Nelson Caldwell ◽  
Jay Strader ◽  
...  
Keyword(s):  
Black Hole ◽  
Adaptive Optics ◽  
Globular Cluster ◽  
Stellar Mass ◽  
High Mass ◽  
Mass Model ◽  
Kinematic Data ◽  
Two Component ◽  
Integral Field ◽  
Rule Out

Abstract We investigate the presence of a central black hole (BH) in B023-G078, M31's most massive globular cluster. We present high-resolution, adaptive-optics assisted, integral-field spectroscopic kinematics from Gemini/NIFS that show a strong rotation (∼20 km s−1) and a velocity dispersion rise toward the center (37 km s−1). We combine the kinematic data with a mass model based on a two-component fit to HST ACS/HRC data of the cluster to estimate the mass of a putative BH. Our dynamical modeling suggests a >3σ detection of a BH component of 9.1 − 2.8 + 2.6 × 10 4 M ⊙ (1σ uncertainties). The inferred stellar mass of the cluster is 6.22 − 0.05 + 0.03 × 10 6 M ⊙ , consistent with previous estimates, thus the BH makes up 1.5% of its mass. We examine whether the observed kinematics are caused by a collection of stellar mass BHs by modeling an extended dark mass as a Plummer profile. The upper limit on the size scale of the extended mass is 0.56 pc (95% confidence), which does not rule out an extended mass. There is compelling evidence that B023-G078 is the tidally stripped nucleus of a galaxy with a stellar mass >109 M ⊙, including its high-mass, two-component luminosity profile, color, metallicity gradient, and spread in metallicity. Given the emerging evidence that the central BH occupation fraction of >109 M ⊙ galaxies is high, the most plausible interpretation of the kinematic data is that B023-G078 hosts a central BH. This makes it the strongest BH detection in a lower-mass (<107 M ⊙) stripped nucleus, and one of the few dynamically detected intermediate-mass BHs.

scholarly journals Not so fast: LB-1 is unlikely to contain a 70 M⊙ black hole

2020 ◽  
Vol 493 (1) ◽  
pp. L22-L27 ◽  
Author(s):  
Kareem El-Badry ◽  
Eliot Quataert
Keyword(s):  
Black Hole ◽  
Radial Velocity ◽  
Emission Line ◽  
Absorption Line ◽  
Relative Velocity ◽  
Stellar Mass ◽  
Accretion Disc ◽  
High Mass ◽  
Mass Ratio ◽  
Rule Out

ABSTRACT The recently discovered binary LB-1 has been reported to contain a ${\sim }70\, \mathrm{M}_{\odot}$ black hole (BH). The evidence for the unprecedentedly high mass of the unseen companion comes from reported radial velocity (RV) variability of the H α emission line, which has been proposed to originate from an accretion disc around a BH. We show that there is in fact no evidence for RV variability of the H α emission line, and that its apparent shifts instead originate from shifts in the luminous star’s H α absorption line. If not accounted for, such shifts will cause a stationary emission line to appear to shift in antiphase with the luminous star. We show that once the template spectrum of a B star is subtracted from the observed Keck/HIRES spectra of LB-1, evidence for RV variability vanishes. Indeed, the data rule out periodic variability of the line with velocity semi-amplitude $K_{\rm H\,\alpha } \gt 1.3\, {\rm {km}} \, s^{-1}$. This strongly suggests that the observed H α emission does not originate primarily from an accretion disc around a BH, and thus that the mass ratio cannot be constrained from the relative velocity amplitudes of the emission and absorption lines. The nature of the unseen companion remains uncertain, but a ‘normal’ stellar-mass BH with mass 5 ≲ M/M⊙ ≲ 20 seems most plausible. The H α emission likely originates primarily from circumbinary material, not from either component of the binary.

scholarly journals Central Dynamics of Globular Clusters: the Case for a Black Hole in ω Centauri

2007 ◽  
Vol 3 (S246) ◽  
pp. 341-345
Author(s):  
Eva Noyola ◽  
Karl Gebhardt ◽  
Marcel Bergmann
Keyword(s):  
Black Hole ◽  
Relaxation Time ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Dwarf Galaxy ◽  
Kinematic Data ◽  
The Core ◽  
Galactic System ◽  
Interesting Candidate ◽  
Radial Anisotropy

AbstractThe globular cluster ω Centauri is one of the largest and most massive members of the Galactic system. Its classification as a globular cluster has been challenged making it a candidate for being the stripped core of an accreted dwarf galaxy; this and the fact that it has one of the largest velocity dispersions for star clusters in our galaxy makes it an interesting candidate for harboring an intermediate mass black hole. We measure the surface brightness profile from integrated light on an HST/ACS image, and find a central power-law cusp of logarithmic slope -0.08. We also analyze Gemini GMOS-IFU kinematic data for a 5”x5” field centered on the nucleus of the cluster, as well as for a field 14″ away. We detect a clear rise in the velocity dispersion from 18.6 kms−1 at 14″ to 23 kms−1 in the center. Given the very large core in ω Cen (2.58'), an increase in the dispersion in the central 10″ is difficult to attribute to stellar remnants, since it requires too many dark remnants and the implied configuration would dissolve quickly given the relaxation time in the core. However, the increase could be consistent with the existence of a central black hole. Assuming a constant M/L for the stars within the core, the dispersion profile from these data and data at larger radii implies a black hole mass of 4.0+0.75−1.0×104M⊙. We have also run flattened, orbit-based models and find a similar mass. In addition, the no black hole case for the orbit model requires an extreme amount of radial anisotropy, which is difficult to preserve given the short relaxation time of the cluster.

scholarly journals Constraining the stellar mass function from the deficiency of tidal disruption flares in the nuclei of massive galaxies

2019 ◽  
Vol 485 (3) ◽  
pp. 4413-4422 ◽  
Author(s):  
Daniel J D’Orazio ◽  
Abraham Loeb ◽  
James Guillochon
Keyword(s):  
Black Hole ◽  
Mass Function ◽  
Stellar Mass ◽  
High Mass ◽  
Black Hole Mass ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Massive Galaxies ◽  
O 10

ABSTRACT The rate of tidal disruption flares (TDFs) per mass of the disrupting black hole encodes information on the present-day mass function (PDMF) of stars in the clusters surrounding super massive black holes. We explore how the shape of the TDF rate with black hole mass can constrain the PDMF, with only weak dependence on black hole spin. We show that existing data can marginally constrain the minimum and maximum masses of stars in the cluster, and the high-mass end of the PDMF slope, as well as the overall TDF rate. With $\mathcal {O}(100)$ TDFs expected to be identified with the Zwicky Transient Facility, the overall rate can be highly constrained, but still with only marginal constraints on the PDMF. However, if ${\lesssim } 10 {{\ \rm per\ cent}}$ of the TDFs expected to be found by LSST over a decade ($\mathcal {O}(10^3)$ TDFs) are identified, then precise and accurate estimates can be made for the minimum stellar mass (within a factor of 2) and the average slope of the high-mass PDMF (to within $\mathcal {O}(10{{\ \rm per\ cent}})$) in nuclear star clusters. This technique could be adapted in the future to probe, in addition to the PDMF, the local black hole mass function and possibly the massive black hole binary population.

scholarly journals VVV SURVEY OBSERVATIONS OF A MICROLENSING STELLAR MASS BLACK HOLE CANDIDATE IN THE FIELD OF THE GLOBULAR CLUSTER NGC 6553

2015 ◽  
Vol 810 (2) ◽  
pp. L20 ◽  
Author(s):  
D. Minniti ◽  
R. Contreras Ramos ◽  
J. Alonso-García ◽  
T. Anguita ◽  
M. Catelan ◽  
...  
Keyword(s):  
Black Hole ◽  
Globular Cluster ◽  
Stellar Mass ◽  
Black Hole Candidate

scholarly journals The Black Hole Mass Function Across Cosmic Times. I. Stellar Black Holes and Light Seed Distribution

2022 ◽  
Vol 924 (2) ◽  
pp. 56
Author(s):  
Alex Sicilia ◽  
Andrea Lapi ◽  
Lumen Boco ◽  
Mario Spera ◽  
Ugo N. Di Carlo ◽  
...  
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
Mass Function ◽  
Stellar Mass ◽  
High Mass ◽  
Minor Effect ◽  
Density Parameter ◽  
Starting Point ◽  
Seed Distribution ◽  
The Impact

Abstract This is the first paper in a series aimed at modeling the black hole (BH) mass function, from the stellar to the intermediate to the (super)massive regime. In the present work, we focus on stellar BHs and provide an ab initio computation of their mass function across cosmic times; we mainly consider the standard, and likely dominant, production channel of stellar-mass BHs constituted by isolated single/binary star evolution. Specifically, we exploit the state-of-the-art stellar and binary evolutionary code SEVN, and couple its outputs with redshift-dependent galaxy statistics and empirical scaling relations involving galaxy metallicity, star formation rate and stellar mass. The resulting relic mass function dN / dVd log m • as a function of the BH mass m • features a rather flat shape up to m • ≈ 50 M ⊙ and then a log-normal decline for larger masses, while its overall normalization at a given mass increases with decreasing redshift. We highlight the contribution to the local mass function from isolated stars evolving into BHs and from binary stellar systems ending up in single or binary BHs. We also include the distortion on the mass function induced by binary BH mergers, finding that it has a minor effect at the high-mass end. We estimate a local stellar BH relic mass density of ρ • ≈ 5 × 107 M ⊙ Mpc−3, which exceeds by more than two orders of magnitude that in supermassive BHs; this translates into an energy density parameter Ω• ≈ 4 × 10−4, implying that the total mass in stellar BHs amounts to ≲1% of the local baryonic matter. We show how our mass function for merging BH binaries compares with the recent estimates from gravitational wave observations by LIGO/Virgo, and discuss the possible implications for dynamical formation of BH binaries in dense environments like star clusters. We address the impact of adopting different binary stellar evolution codes (SEVN and COSMIC) on the mass function, and find the main differences to occur at the high-mass end, in connection with the numerical treatment of stellar binary evolution effects. We highlight that our results can provide a firm theoretical basis for a physically motivated light seed distribution at high redshift, to be implemented in semi-analytic and numerical models of BH formation and evolution. Finally, we stress that the present work can constitute a starting point to investigate the origin of heavy seeds and the growth of (super)massive BHs in high-redshift star-forming galaxies, that we will pursue in forthcoming papers.

scholarly journals First results from the TNG50 simulation: galactic outflows driven by supernovae and black hole feedback

2019 ◽  
Vol 490 (3) ◽  
pp. 3234-3261 ◽  
Author(s):  
Dylan Nelson ◽  
Annalisa Pillepich ◽  
Volker Springel ◽  
Rüdiger Pakmor ◽  
Rainer Weinberger ◽  
...  
Keyword(s):  
Black Hole ◽  
Main Sequence ◽  
Stellar Mass ◽  
High Mass ◽  
Complex Behaviour ◽  
Massive Galaxies ◽  
Star Forming ◽  
Outflow Velocity ◽  
Galactic Outflows ◽  
First Results

Abstract We present the new TNG50 cosmological, magnetohydrodynamical simulation – the third and final volume of the IllustrisTNG project. This simulation occupies a unique combination of large volume and high resolution, with a 50 Mpc box sampled by 21603 gas cells (baryon mass of 8 × 104 M⊙). The median spatial resolution of star-forming interstellar medium gas is ∼100−140 pc. This resolution approaches or exceeds that of modern ‘zoom’ simulations of individual massive galaxies, while the volume contains ∼20 000 resolved galaxies with $M_\star \gtrsim 10^7$ M⊙. Herein we show first results from TNG50, focusing on galactic outflows driven by supernovae as well as supermassive black hole feedback. We find that the outflow mass loading is a non-monotonic function of galaxy stellar mass, turning over and rising rapidly above 1010.5 M⊙ due to the action of the central black hole (BH). The outflow velocity increases with stellar mass, and at fixed mass it is faster at higher redshift. The TNG model can produce high-velocity, multiphase outflows that include cool, dense components. These outflows reach speeds in excess of 3000 km s−1 out to 20 kpc with an ejective, BH-driven origin. Critically, we show how the relative simplicity of model inputs (and scalings) at the injection scale produces complex behaviour at galactic and halo scales. For example, despite isotropic wind launching, outflows exhibit natural collimation and an emergent bipolarity. Furthermore, galaxies above the star-forming main sequence drive faster outflows, although this correlation inverts at high mass with the onset of quenching, whereby low-luminosity, slowly accreting, massive BHs drive the strongest outflows.

scholarly journals Features of globular cluster’s dynamics with an intermediate-mass black hole

2018 ◽  
Vol 27 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Marina V. Ryabova ◽  
Alena S. Gorban ◽  
Yuri A. Shchekinov ◽  
Evgenii O. Vasiliev
Keyword(s):  
Black Hole ◽  
Binary System ◽  
Globular Cluster ◽  
Binary Stars ◽  
Stellar Mass ◽  
Core Collapse ◽  
Intermediate Mass

Abstract In this paper, we address the question of how a central intermediate-mass black hole (IMBH) in a globular cluster (GC) affects dynamics, core collapse, and formation of the binary population. It is shown that the central IMBH forms a binary system that affects dynamics of stars in the cluster significantly. The presence of an intermediate-mass black hole with mass ≥ 1.0-1.7%of the total stellar mass in the cluster inhibits the formation of binary stars population.

scholarly journals Adaptive Optics-Based Measurements of the Black Hole in Abell 2162–BCG

2009 ◽  
Vol 5 (S267) ◽  
pp. 208-208
Author(s):  
Nicholas J. McConnell ◽  
James R. Graham ◽  
Chung-Pei Ma ◽  
Karl Gebhardt ◽  
Tod R. Lauer
Keyword(s):  
Black Hole ◽  
Adaptive Optics ◽  
Black Hole Mass ◽  
Central Black Hole ◽  
Cluster Galaxy ◽  
Ongoing Effort ◽  
Field Unit ◽  
Guide Star ◽  
Laser Guide ◽  
Integral Field

We present preliminary measurements of the central black hole mass MBH, and stellar mass-to-light ratio M*/LR, in the Brightest Cluster Galaxy of Abell 2162 (A2162–BCG), using integral-field unit (IFU) data from OSIRIS on Keck 2 with laser guide star adaptive optics (LGS-AO). Our results demonstrate early success in an ongoing effort to obtain stellar dynamical measurements of MBH in nine BCGs using ground-based AO.

scholarly journals NIR integral field spectroscopy of high mass young stellar objects

2012 ◽  
Vol 8 (S292) ◽  
pp. 53-53
Author(s):  
K. Murakawa ◽  
S. L. Lumsden ◽  
R. D. Oudmaijer ◽  
B. Davies ◽  
M. G. Hoare
Keyword(s):  
Gas Phase ◽  
Adaptive Optics ◽  
Three Dimensional ◽  
Young Stellar Objects ◽  
High Mass ◽  
Spectral Features ◽  
Stellar Objects ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
Integral Field

AbstractWe present K-band Integral Field Spectroscopy of six high mass young stellar objects (IRAS~18151–1208, AFGL~2136, S106~IRS4, V645 Cyg, IRAS~19065+0526, and G082.5682+ 00.4040) obtained using the adaptive optics assisted NIFS instrument mounted on the Gemini North telescope. The targets are chosen from the Red MSX Source survey led by University of Leeds. The data show the spectral features of Brγ, H2, and gas phase CO emissions and absorptions with a spectral resolution of R ≈ 5500, which allow a three-dimensional spectro-astrometric analysis of the line emissions. We discuss the results of the ionized jets and winds, and rotating CO torus.

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